Pyrethrum

Description

A natural mixture of six pyrethrin compounds obtained from chrysanthemum flowers that has been used for centuries as an insecticide. For use as an insecticide, the flowers were dried then mixed with water. They were also used as companion plants to minimize garden pests such as aphids, leafhoppers, ticks and rabbits.

Tradenames

• Agriculture: PyGanic, Evergreen, ExciteR, Diacide, Safer Brand Yard & Garden
• Household: Raid (select natural formulas), Drione, Revenge, Pursue, Kincho (mosquito coils)
• Lice treatments: RID, Pronto, A-200, R&C Shampoo
• Historical names: Zacherlin (19th-century European insect powder), Pulvis Insectis, Persian insect powder (used by Napoleon's army)

Risks

• Highly toxic to cats, fish and aquatic invertebrates
• Low toxicity to humans and birds
• Breaks down rapidly in sunlight within 12-24 hours
• Toxic by ingestion, inhalation and skin contact. LD50 = 584-900 mg/kg.
• Persons sensitive to ragweed will be prone to pyrethrin allergic reactions.

Resources and Citations

• MuseumPests.net: Pesticide Database
• Wikipedia: Pyrethrum Accessed July 2023